JP2007017713A - Belt used for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve bonding durability, and to prolong the duration of life by devising a method (bonding method) of bonding a substrate layer and an elastic layer, for solving the problem of the conventional techniques, by increasing the bonding strength between the substrate layer and the elastic layer (elastic rubber) and moderating the shearing force applied to the boundary between the substrate layer and the elastic layer in the rotational direction of a roller, in a belt for an image forming apparatus constituted by bonding the substrate layer and the elastic layer. <P>SOLUTION: The belt used for the image forming apparatus is provided such that in a belt member which is constituted by bonding a substrate layer 2 and an elastic layer 3 and is used for the image forming apparatus, the substrate layer 2 has a plurality of wedge grooves 4, whose angles in cut directions are alternately reversed in the surface of the substrate layer 2, and the elastic rubber is bonded on the surface of the substrate layer 2, to form the elastic layer 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a belt used in an image forming apparatus such as an electrophotographic copying machine, a printer, or a facsimile, and more particularly to a belt used in an image forming apparatus formed by bonding a base layer and an elastic layer.

  In general, in an image forming apparatus such as an electrophotographic copying machine, a printer, or a facsimile, a toner image is formed by adhering toner in a predetermined shape to a paper surface, and then a belt (rubber is bonded to a base layer made of polyimide or the like ( Hereinafter, the paper on which the toner image is formed is passed between a fixing belt) and a roller (hereinafter referred to as a pressure roller) in which rubber is bonded to a core metal. At this time, pressure is applied to the toner adhering to the paper surface by a rubber roller (hereinafter referred to as a fixing roller) that is pressed from the inner peripheral surface side of the fixing belt and a pressure roller that is pressed from the outer peripheral surface side of the fixing belt, and A system is adopted in which the toner is fixed on the paper surface by heating.

However, when fixing is performed by such a method, when the paper passes between the fixing belt and the pressure roller, the paper is conveyed and discharged at the same time while being pressed against the paper. The interface between the base layer and the elastic rubber of the fixing belt causes a displacement force and the expansion and contraction due to the elastic repulsion of the rubber. There was a problem.
Conventionally, in order to prevent such peeling, a high heat-resistant adhesive has been selected and measures have been taken to increase the adhesive strength. It was very difficult to maintain for a long time.

Japanese Patent Application Laid-Open No. 2004-255828 (Patent Document 1, Composite Belt and Manufacturing Method Thereof) discloses a composite belt for an image forming apparatus in which a tubular base material layer, an elastic body layer, and a fluororesin layer are laminated. It has been proposed to form a recess on the elastic layer side of the interface that bonds the body layer and the fluororesin layer and maintain the adhesive force by the anchor effect.
As shown in FIG. 3, the composite belt described in Patent Document 1 is a seamless composite tubular body including a tubular base layer 11, an elastic body layer 12, and a fluororesin layer 13 in this order, and is elastic. A recess is formed by blasting on the surface of the body layer 12 and the fluororesin layer 13 and on the elastic layer 12 side, and the fluororesin 14 is embedded in the recess, and the fluororesin 14 and the fluororesin 13 Is to increase the adhesion between the elastic layer 12 and the fluororesin layer 13 by fusing and integrating.
However, in a case where bending is repeated over a long period of time, such as a fixing belt for an image forming apparatus, it is only necessary to form a recess on the surface of one layer and partially embed another layer in the recess to provide an anchor effect. However, it cannot provide a sufficient adhesive force that can withstand the displacement force and expansion / contraction of the interface, resulting in poor durability.

In addition, in a roller used in an image forming apparatus, in order to improve the adhesion between the inner layer constituting the roller and the outer layer made of rubber or synthetic resin, it has already been possible to form an uneven shape between the inner and outer layers. Proposed.
For example, in Japanese Patent Application Laid-Open No. 2004-85628 (Patent Document 2, roller used in an image forming apparatus), as shown in FIG. 4, a plurality of grooves 23 in the axial direction on the surface of a roller metal core 21. And a roller for an image forming apparatus in which an elastic rubber 22 is vulcanized and bonded after applying an adhesive on the surface having these grooves 23. In this roller, since the elastic rubber 22 has a shape that penetrates and fits into the groove 23, the shearing force applied to the interface between the core metal and the elastic rubber with respect to the roller rotation direction is relieved by the anchor effect. The adhesive strength (adhesiveness) is relatively increased.
As described above, the roller for the image forming apparatus of Patent Document 2 is obtained by processing a groove parallel to a rigid body such as a roller core, but repeatedly bends like a belt for the image forming apparatus. However, the anchor effect is low only with the parallel grooves, and a sufficient adhesive strength that can withstand the displacement force and expansion / contraction of the interface cannot be obtained.

Japanese Patent Laid-Open No. 10-48985 (Patent Document 3, fixing roller and manufacturing method thereof) describes a roller similar to the roller for an image forming apparatus described in Patent Document 2, and includes a fixing roller. The concavo-convex convex portion formed on the surface of the core metal strikes a wedge against the outer layers (adhesive layer and release layer) covering the outer periphery of the core metal when the fixing roller rotates for paper conveyance. It is a shape. The fixing roller can suppress a decrease in the adhesion force between the cored bar and the outer layer covering the outer periphery due to the force generated in the reverse rotation direction with respect to the direction in which the fixing roller rotates for paper conveyance.
As described above, the fixing roller for the image forming apparatus is formed by forming a wedge-shaped unevenness on the fixing roller core metal. However, in the case where the belt is repeatedly bent like the belt for the image forming apparatus, An anchor effect is low only with wedge-shaped irregularities having a certain angle, and a sufficient adhesive strength that can withstand the displacement force and expansion / contraction of the interface cannot be obtained.

JP-A-8-339119 (Patent Document 4, double-layer rubber roller and method for manufacturing the same) has an outer diameter that is substantially the same as the inner diameter of the cylindrical mold. A vulcanized solid rubber tube with a plurality of axial grooves formed in advance is placed, and a core shaft with an unfoamed sponge rubber is attached to the center of the mold, and the sponge rubber is expanded and expanded. A method of manufacturing a two-layer rubber roller is described in which the sponge rubber is vulcanized and vulcanized and bonded to the inner surface of the solid rubber tube after the inner surface of the solid rubber tube is in close contact with the inner surface of the solid rubber tube. The “double-layer rubber roller” is also described.
As described above, the roller for the image forming apparatus has a groove on the inner surface of the solid rubber as a surface layer. However, in the case where the bending is repeated like a fixing belt for the image forming apparatus, only the parallel groove is provided. In this case, the anchor effect is low, and it is impossible to obtain sufficient adhesive strength that can withstand the displacement force and expansion / contraction of the interface.

JP 2004-255828 A JP 2004-85628 A Japanese Patent Laid-Open No. 10-48985 JP-A-8-339119

  The present invention provides a belt for an image forming apparatus in which a base layer and an elastic layer are bonded to devise a bonding method (bonding method) between the base layer and the elastic layer in order to solve the above-described problems of the prior art. By increasing the adhesive strength between the base layer and the elastic layer (elastic rubber) and relaxing the shearing force applied to the interface between the base layer and the elastic layer in the roller rotation direction, the adhesion durability is improved and the service life is increased. The extension is the technical issue.

The means for solving the above-mentioned problem is basically to form a plurality of wedge-shaped grooves on the surface of the base layer in the axial direction of the belt in an image forming apparatus belt in which an elastic layer is bonded to the base layer. It is.
(1) A belt for an image forming apparatus according to the present invention is premised on a belt member used for an image forming apparatus formed by bonding a base layer and an elastic layer.
The base layer is provided with a plurality of wedge-shaped grooves on the surface of which the cutting directions alternately have opposite angles, and an elastic rubber is bonded onto the surface of the base layer to form an elastic layer.
According to such a configuration, the elastic rubber forming the elastic layer enters and fits into the plurality of wedge-shaped grooves formed at alternately opposite angles on the surface of the base layer. The adhesive force can be relatively increased by the anchor effect.

(2) In the belt for the image forming apparatus, the wedge-shaped groove can be provided in the axial direction of the belt.
According to this configuration, since the groove on the surface of the base layer is in the axial direction of the belt, the shear force generated at the base layer-elastic rubber interface generated in the belt running direction can be reduced, and the adhesive force is relatively increased. Can be achieved.

(3) In the belt for an image forming apparatus, the wedge-shaped groove has an angle θ between the surface of the base layer and one of the planes forming the wedge-shaped groove, θ <90 °. It is formed as follows.
According to this configuration, since the angle θ formed between the surface of the base layer and the flat portion of the wedge-shaped groove is θ <90 °, the anchor effect can be obtained regardless of which shear force is generated. The shearing force at the base layer-elastic rubber interface can be relaxed.

(4) In the belt for the image forming apparatus, the depth d of the wedge-shaped groove is 4 μm or more.
According to this configuration, since the depth d of the wedge-shaped groove is 4 μm or more, the anchor effect obtained by the base layer-elastic rubber fitting can be sufficiently exhibited.

(5) Further, in the belt for the image forming apparatus, the opening width W of the wedge-shaped groove is 1 / 5d <W <1 / 2d.
According to this configuration, since the opening width W of the wedge-shaped groove is 1 / 5d <W <1 / 2d, the elastic rubber can completely penetrate to the bottom of the wedge-shaped groove, and Reduction of the anchor effect obtained by the base layer-elastic rubber fitting can be prevented.

(6) The method for manufacturing a belt for an image forming apparatus according to the present invention is based on the premise of a method for manufacturing a belt member used in an image forming apparatus by bonding a base layer and an elastic layer.
After forming a base layer provided with a plurality of wedge-shaped grooves with inversion angles alternately in the axial direction of the belt on the surface, and applying an adhesive on the outer peripheral surface of the base layer, elastic rubber is applied. It is to apply and vulcanize and bond.
According to such a configuration, the elastic rubber forming the elastic layer enters and fits into the plurality of wedge-shaped grooves formed at alternately opposite angles on the surface of the base layer. It is possible to manufacture a belt for an image forming apparatus in which the adhesive force is relatively increased by the anchor effect.

The effects of the present invention are summarized according to the claims as follows.
(1) Inventions according to claims 1 to 6 In a belt for an image forming apparatus formed by bonding a base layer and an elastic layer, the elastic rubber forming the elastic layer has an angle in the opposite direction alternately on the surface of the base layer. By intruding and fitting into a plurality of wedge-shaped grooves formed by holding, it is possible to increase the adhesive force relatively by the anchor effect of both, so the belt can be heated or pressed Even when used, peeling at the base layer-elastic rubber interface can be prevented.
Further, by setting the groove on the surface of the base layer in the axial direction of the belt, the shearing force at the base layer-elastic rubber interface generated in the running direction of the belt can be relaxed, so that the adhesive force is relatively increased. be able to.

Since the angle θ formed between the surface of the base layer and the flat portion of the groove is θ <90 °, the anchor effect can be obtained regardless of the direction in which shearing force is generated, and shear at the base layer-elastic rubber interface is achieved. The force can be relaxed and the adhesive force can be relatively increased.
In addition, since the depth d of the wedge-shaped groove is 4 μm or more, the anchor effect obtained by the base layer-elastic rubber fitting can be sufficiently exhibited, and the adhesive force can be relatively increased. .
Further, since the opening width W of the wedge-shaped groove is 1 / 5d <W <1 / 2d, the elastic rubber can be completely penetrated to the bottom of the wedge-shaped groove, and the base layer-elasticity Since the reduction of the anchor effect obtained by the rubber fitting can be prevented, the shear force can be relaxed and the adhesive force can be relatively increased.

(2) The invention according to claim 7 In the method of manufacturing a belt member used in an image forming apparatus by bonding a base layer and an elastic layer, a plurality of wedge-shaped grooves whose cutting directions are alternately opposite to each other are formed. A base layer provided on the surface is molded, and an adhesive is applied to the outer peripheral surface of the base layer, and then elastic rubber is applied and vulcanized to adhere the elastic rubber forming the elastic layer alternately on the surface of the base layer. Since it penetrates into and fits into multiple wedge-shaped grooves formed at opposite angles, the adhesive effect can be increased relatively by the anchor effect of both, and the belt can be heated or pressed. The belt for an image forming apparatus that can prevent peeling at the interface between the base layer and the elastic rubber can be produced.

(3) The invention according to claim 8 The image forming apparatus is equipped with a fixing belt having an increased adhesive force between the base layer and the elastic rubber, and does not cause peeling of the elastic layer on the fixing belt. The replacement cost is suppressed, and a good image can be provided over a long period of time.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram of a belt for an image forming apparatus, and FIG. 2 is an explanatory diagram regarding a base layer-elastic rubber interface of the belt for an image forming apparatus.
The belt 1 used in the image forming apparatus is configured by adhering an elastic rubber 3 to a base layer 2, and a plurality of wedge-shaped grooves 4 are formed in the axial direction on the surface of the base layer 2. The elastic rubber 3 is adhered on the surface of the base layer 2 having the grooves 4.
The wedge-shaped groove 4 has an angle θ (see FIG. 2B) formed by the surface of the base layer 2 and one of the planes forming the groove 4 in a range of θ <90 °, and The grooves 4 are formed so that the cutting directions are alternately opposite to each other. The main feature is that the depth d and the opening width W (see FIG. 2B) of the wedge-shaped groove 4 are d> 4 μm or more and 1 / 5d <W <1 / 2d, respectively. ing.

The base layer 2 of the belt 1 for an image forming apparatus is made of polyimide, and is molded using a method such as centrifugal molding, dipping, or extrusion molding. Since a plurality of rollers are arranged inside the base layer 2, the circumference is preferably 120 mm or more, but in this example, it is 179 mm. The thickness of the base layer 2 is preferably 50 to 200 μm because it requires strength and flexibility to run the belt 1 while being stretched, but in this example, it is 90 μm.
After the base layer 2 is molded in this way, a plurality of wedge-shaped grooves 4 whose cut directions are alternately opposite to each other are formed in the axial direction of the belt by machining on the surface of the base layer 2. When the base layer 2 is molded by extrusion molding, the groove 4 can be formed simultaneously with the molding.
Next, after applying an adhesive (not shown) to the outer peripheral surface of the base layer 2, the elastic rubber 3 is applied so as to have a thickness of 150 μm by spray coating, dipping or the like, and vulcanized and adhered to the belt 1. Manufactured. The applied elastic rubber 3 penetrates into the wedge-shaped grooves 4 in which the cutting directions formed on the surface of the base layer 2 alternately have angles opposite to each other. The adhesive force can be relatively increased, and peeling at the base layer-elastic rubber interface can be prevented even when the belt is used in a heated state or a pressure contact state.

The shearing force that peels the base layer 2 and the elastic rubber 3 is mainly a shearing force due to the bending of the belt 1 or the difference in roller speed when traveling while being sandwiched between two rollers. Therefore, the direction of the wedge-shaped groove 4 is formed in the axial direction of the belt opposite to the shearing force. With this configuration, the shearing force at the base layer-elastic rubber interface generated in the running direction of the belt is reduced. Then you can.
The speeds of the two rollers that press the belt 1 are the same in design and no difference in speed occurs. However, it is impossible to achieve the same speed for all roller combinations due to variations in the outer diameter of the rollers. . With this combination, the direction of the shearing force of the belt due to the difference in roller speed is generated in two directions, the case of the belt running direction and the opposite direction. For this reason, the cutting direction of the wedge-shaped groove 4 provided in the base layer 2 is alternately changed in the reverse direction, and the angle θ formed between the surface of the base layer 2 and the flat portion forming the wedge-shaped groove 4 is θ < Since it is set at 90 °, the anchor effect can be obtained regardless of the shearing force generated in any direction, and the shearing force at the interface between the base layer and the elastic rubber can be relaxed to relatively increase the adhesive force. It is possible to plan.
On the other hand, when θ> 90 °, since the shearing force is in a direction inducing separation, the effect of the wedge-shaped groove 4 is reduced.

上記表１において、○印は界面剥離部無し、×印は界面剥離部有り、そして、※印は１０００時間経過前に剥離が発生したことを示している。 The belt for the image forming apparatus of the present invention is used as a fixing belt to constitute a normal fixing unit. After running for 1000 hours, the base layer 2 and the elastic rubber 3 are forcibly peeled off, and the base layer and the elastic rubber are separated. The peeling state was investigated. The results are shown in Table 1.

In Table 1 above, ◯ indicates that there is no interface peeling portion, X indicates that there is an interface peeling portion, and * indicates that peeling occurred before 1000 hours.

The adhesion between the base layer and the elastic rubber (no interfacial peeling portion) requires that the elastic rubber 3 is broken in a state where it is forced to peel off. In such a state, sufficient adhesive force has been generated. According to the results of Table 1 above, if the depth d of the wedge-shaped groove 4 is 4 μm or more, the anchoring effect obtained by the base layer-elastic rubber fitting is sufficiently exerted to reduce the shearing force, Since the adhesive force can be relatively increased, a sufficient adhesion state can be maintained even after 1000 hours. On the other hand, when the depth d is 3 μm, the effect of reducing the shearing force cannot be expected sufficiently.
The effect of the width W of the wedge-shaped groove 4 is related to the depth d of the groove 4. If 1 / 5d <W <1 / 2d, elastic rubber is applied to the bottom of the wedge-shaped groove 4. It can be completely penetrated and the anchor effect obtained by the base layer-elastic rubber fitting can be fully exerted, so it is possible to relax the shear force and relatively increase the adhesive force It is.
On the other hand, if W <1 / 5d, peeling occurs before 1000 hours. This is because the elastic rubber 3 does not sufficiently permeate inside the wedge-shaped groove 4 so that bubbles remain, and an action of peeling the elastic rubber 3 due to expansion of the bubbles due to heating works.

このように、本発明のベルトを画像形成装置の定着ベルトとして搭載することにより、定着ベルトにおける弾性層の剥離等を発生しないため、部品の交換コストが抑えられ、長期間に亘り良好な画像を得ることができる。 Table 2 shows the results obtained by mounting the belt of the present invention as a fixing belt in an image forming apparatus and operating 100,000 copies. No peeling between the base layer and the elastic rubber occurred during the operation per 10,000 units.

As described above, by mounting the belt of the present invention as a fixing belt of an image forming apparatus, the elastic layer is not peeled off from the fixing belt, so that the replacement cost of parts can be suppressed, and a good image can be obtained over a long period of time. Obtainable.

  FIG. 2C shows a modification of the cross-sectional shape of the wedge-shaped groove 4 of the base layer 2. The cross-sectional shape of the wedge-shaped groove 4 in this figure has an R shape in which the lower side (base layer side) is rounded. Even when such a groove is employed, the same effect as that of the wedge-shaped groove shown in FIG. The wedge-shaped groove in the present invention is not limited to these shapes, and various shapes can be adopted as long as the groove shape can solve the problems of the present invention.

FIG. 2A is a schematic view of a fixing belt according to an embodiment of the present invention, FIG. 3A is an external view, and FIG. These are explanatory drawings regarding the base layer-elastic rubber interface of the fixing belt according to the embodiment of the present invention, (a) is an enlarged sectional view, (b) is an explanatory view showing the sectional shape of a wedge-shaped groove, (c) ) Is an explanatory view showing a modified example of the wedge-shaped groove. FIG. 4 is a schematic diagram of a conventional fixing belt for an image forming apparatus, where (a) is a cross-sectional view and (b) is an enlarged cross-sectional view. FIG. 4 is a schematic view of a conventional roller for an image forming apparatus, in which (a) is a side sectional view and (b) is a B-B ′ sectional view of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Belt 2 ... Base layer 3 ... Elastic layer (elastic rubber) 4 ... Groove (wedge-shaped groove)

Claims (8)

In a belt member used in an image forming apparatus formed by bonding a base layer (2) and an elastic layer (3),
The base layer (2) has a plurality of wedge-shaped grooves (4) on its surface, and an elastic layer (3) is formed by adhering elastic rubber on the surface of the base layer (2). A belt used in an image forming apparatus. In a belt member used in an image forming apparatus formed by bonding a base layer (2) and an elastic layer (3),
The base layer (2) is provided with a plurality of wedge-shaped grooves (4) whose incision directions are alternately opposite to each other on the surface, and an elastic rubber is bonded onto the surface of the base layer (2) to be elastic. A belt used in an image forming apparatus, wherein the layer (3) is formed.   The belt used for an image forming apparatus according to claim 1 or 2, wherein the wedge-shaped groove (4) is provided in an axial direction of the belt (1).   The wedge-shaped groove (4) is formed so that the angle θ formed by the surface of the base layer (2) and one of the planes forming the wedge-shaped groove (4) is θ <90 °. The belt used in the image forming apparatus according to any one of claims 1 to 3, wherein the belt is used.   The belt used for an image forming apparatus according to any one of claims 1 to 4, wherein a depth d of the wedge-shaped groove (4) is 4 µm or more.   6. The belt used for an image forming apparatus according to claim 5, wherein an opening width W of the wedge-shaped groove (4) satisfies 1 / 5d <W <1 / 2d. In a method of manufacturing a belt member used in an image forming apparatus by bonding a base layer (2) and an elastic layer (3),
A base layer (2) provided with a plurality of wedge-shaped grooves (4) having inversion directions alternately opposite to each other in the axial direction of the belt (1) is molded,
After applying an adhesive to the outer peripheral surface of the base layer (2),
A method for producing a belt used in an image forming apparatus, characterized in that an elastic rubber (3) is applied and vulcanized and bonded.   7. An image forming apparatus, wherein the belt (1) used in the image forming apparatus according to claim 1 is used as a fixing belt for fixing toner.

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